Umar ibn al-Khattab reported: A man from the Jews said, “O leader of the believers, there is a verse you recite in your book and, had it been revealed to us as Jews, we would have taken that day as a celebration.” Umar said, “Which verse is it?” The man recited the verse, “Today I have completed your religion for you, perfected My favor upon you, and have chosen Islam as your religion.” (5:3)
Umar said, “I know the day and place in which this verse was revealed to the Prophet, peace and blessings be upon him. It was while he was standing on the day of Arafat on Friday.”
Source: Ṣaḥīḥ al-Bukhārī 45, Ṣaḥīḥ Muslim 3017
Grade: Muttafaqun Alayhi (authenticity agreed upon) according to Al-Bukhari and Muslim
عَنْ عُمَرَ بْنِ الْخَطَّابِ أَنَّ رَجُلًا مِنْ الْيَهُودِ قَالَ لَهُ يَا أَمِيرَ الْمُؤْمِنِينَ آيَةٌ فِي كِتَابِكُمْ تَقْرَءُونَهَا لَوْ عَلَيْنَا مَعْشَرَ الْيَهُودِ نَزَلَتْ لَاتَّخَذْنَا ذَلِكَ الْيَوْمَ عِيدًا قَالَ أَيُّ آيَةٍ قَالَ الْيَوْمَ أَكْمَلْتُ لَكُمْ دِينَكُمْ وَأَتْمَمْتُ عَلَيْكُمْ نِعْمَتِي وَرَضِيتُ لَكُمْ الْإِسْلَامَ دِينًا قَالَ عُمَرُ قَدْ عَرَفْنَا ذَلِكَ الْيَوْمَ وَالْمَكَانَ الَّذِي نَزَلَتْ فِيهِ عَلَى النَّبِيِّ صَلَّى اللَّهُ عَلَيْهِ وَسَلَّمَ وَهُوَ قَائِمٌ بِعَرَفَةَ يَوْمَ جُمُعَةٍ
45 صحيح البخاري كتاب الإيمان باب زيادة الإيمان ونقصانه
3017 صحيح مسلم كتاب التفسير